Distribution-valve for steam-engines.



J. STUMPF.

DISTBIBUTIO APPLIO VE FOR STEAM ENGINES. FILED our. 25, 1910.

Patented Nov. 19,1912.

"flow type, that is those steam engines in J'OHANN STUMPF, 0F BERLIN, GERMANY.

DISTRIBUTION-VALVE FOR STEAM-ENGINES.

I To all whom it may concerm.

Be it known that I, JOHANN STL'MPF, a

subject of the King of Prussia, and a resi-- 1 i dentof Berlin, Germany, have invented certain new and useful Improvements in Dis-- tribution-Valves of Steam-Engines, of which the following is a specification.

' This'v invention relates to improvements in "the distribution valves of steam engines 'cspecially steam engines of the uni-directional I which steam enters the cylinder at one end 5 and exhausts toward the piston either of its working stroke.

through ports in the piston or through ports controlled by the piston at or near the end The object of the present invention is to provide a form of lift valve which will meet the requirements of a distribution valve for steam engines. The invention is 1llust-rated in one convenient form in the accompanying drawing which is a cross sectional elevation through a valve according to this invention, and part of the casing therefor.

'areciprocating rod (Z, operated in any convcnient'manner has attached to it a two faced or double beat valve a, the faces of which-are formed on one plece of metal,

preferably steel. This valve is provided with an extended boss f, guided on a projecting I 'guide f", formed 'on a detachable part f The detachable part 9 is fixed to the casing .h, by means of pins 11-, and carries one of the seats of the valve. The other seat is-formed on the casing 72 being cast therewith. Itwill be seen that the detachable 5 part- 9 extends from the wall of the casing h, toward the cast seat I), and thereby the seats L, and 0 are brought more nearly together. In order however, to provide ample area of flow for the steam or other fluid. the

part- 9 is undercut at 7), relatively to the seat 0 lVith this arrangement the valve seats may be arranged very closely together Q thereby diminishing the length of the valve and consequently its weight and also dim nlshmg the relative expansion of the parts under varying temperature. This last fact will be readily understood as it is clear that by diminishing the length of the tubu; lar body subjected to the variable heating action, the amount of the expansion will also be diminished.

The valve itself is formed of a'rigid body part a, which terminatesin a rigidly sup- Specification of Letters Patent.

Patented Nev; is, 51912.

Application filed October 25, 1910. Serial No. 588,936 1 l supported face overhangs the'rigid face by an amount 6. The valve thus has two couples one of which (at b) is forcedinto en'- gagement by the forward pressure-of the fluid to be controlled. This .valve face is peripherally freely flexible to conform to distortions of its seat resulting from varying temperature conditions while at thejsame" time it is capable, owing to its resiliency, of opening under a slight excess ofback pressure such as may occur on the compression stroke in a uni-directional flow engine. The valve is normally held closed by a spring 9, and the rod a, only acts to raise the valve against the pressure of'the spring 9. If there is no pressure outside the'valve, the resilient face should just'rest on the seat Z2, and of course in such a case there is'no" bending moment on the cantaliver ring m about the points 3 I have called the resilient annular web a cantaliver ring of the width a"y, as it may be conveniently considered as made of an infinite number-of radial cantalivers fixed at y, and uniformly loaded by the pressure external to the valve. This pressure tends to force, the. resiliently supported face into engagement with, its coacting seat. i i

This form of valve can thus accommodate itself to such variations in the relative positions of the seats and faces as occur in practice due to. varying pressures and temperatures.-

In ordinary screw down stop valves, the

available closing pressure is considerable and in double faced valves it may be sufic ient to strain the valve to bring both faces into adequate co-action with their seats In distribution valves,'however, the available closing pressure is limited as. it would 'involve'the application of too much energy to operate the valve should these valves be held down by excessive pressure. In distribubody on the annulus w-y less 6.

tion valves therefore, it is of the utmost importance to obtain the best possible closure with the minimum amount of power. In the-form of valve illustrated, the spring 9, acts to hold the valve down with the rigidly co-acting face and seat in effective cooperation. Practically none of this spring pressure is used to hold the resilient valve face to its seat. The spring 9, thus does not require that any internal strain be produced in the valve as has been customary in double beat valves with a resiliently co-acting pair of faces and seats as hithereto proposed. For this reason the spring q, need not be heavy and the power necessary to operate the valve is thus reduced.

The closing pressure of the resilient face on its seat 6, is obtained by the resultant of the downward pressure on the cantaliver zry, and the upward pressure of the rigid This practically amounts to the pressure on the annulus e, that is'on the overhanging annulus. A consideration of the forces acting on the vannular web 9, and the conditions required in an ideal valve point to the fact that the annulus 6, should be -}ths of the width ofthe Web, that is to say the resilient face should overhang the rigid face by an amount which is iihree eighths of the width of the resilient We In steam engines Wherethe valve systeu'i above described is used for controlling admission of the steam to the cylinder, the resilient Web g is, at the end of compression,

subjected on its upper side to the boiler pressure and on its lower side to the compression pressure of the cylinder. If the compression pressure is excessive, as it is apt to be occasionally in uni-directional flow engines, the Web 9, Will rise and thus relieve compression. The valve a, is of course only partially balanced but as the valve is, (hiring running, opened at the end of compression, the force required to open it is small and is usually only slightly in excess of the resistance of the spring 5 It will also be readily understood by those engaged in this art that the chief point of importance resides in combining all the above features in a valve which is made in one piece of metal as composite valves made of separate parts would be quite useless as distribution valves in steam engines, compressors or the like.

I claim: 1. A valve,-for controlling the passage of I fluid in a plurality of streams, having two couples of meeting faces, one couple being resilient, urged to closing position by the forward "pressure of the fluid to be controlled, and capable, by its resiliency, of opening under a slight excess of backward pressure, independently ofthe opening .of the other couple.

2. The combination with rigid valve seats in different planes, of a metallic valve body having a plurality of valve faces integral therewith, in different planes, and controlling the flow of parallel streams, one of said faces being freely flexible peripherally with respect to its normal plane and subjected to fluid pressure to urge it to its seat.

3. .A double seat valve comprising a reciprocating valve spindle, an apertured valve body connected to said spindle and carrying a rigid annular valve face, and an integral resilient annular flange having a peripheral valve face which is freely flexible with respect to its normal plane.

4. A double seat valve comprising a reciprocating valve spindle, an apertured valve member connected to said spindle and carrying a rigid annular valve face and a resilient annular web having a valve face adjacent to its outer periphery overhanging said rigid valve face by an amo-untsubstanti ally three eighths of the width of said resilient web.

5. In combination a valve casing having a valve seat formed thereon, a detachable seat carrying part fixed in said casing, the seat on said detachable part being nearer to the a valve seat formed thereon, a detachable. seat-carrying part fixed in sa d casing the seat on said detachable part being nearer to the seat in the casing than the part of said casing to which said detachable part is fixed, said detachable part being also undercut relatively to the valve seat thereon, a guide piece arranged centrally on said detachable part, a double faced valve, the faces of wh ch co-act with the seats in said casing and 52nd. detachable part respectively and a centrally arranged part on said valve fitting tov slide on the centrally arranged guide on the detachable part.- v v Signed at Berlin, Germany, this 8 day of October 1910.

JOHANN STUMPF.

WVitnesses VVILLY \VINTER, HERMANN BoNi'N. 

